In some situations a particular signal to be broadcast by radio is broadcast at two or more different frequencies. This provides an advantage when weather conditions prevent good reception on one of the frequencies. For example, the National Bureau of Standards broadcasts its time signals at 5 MHz, 10 MHz, 15 MHz, and 20 MHz. If one of these frequencies is blocked by weather conditions or other problems, the radio receiver is simply retuned to a frequency that is not blocked. In critical situations, however, important information may be lost during the retuning process if the receiver is tuned to a frequency which is blocked when that information is transmitted. Therefore, in such situations, a plurality of frequency diversity receivers, one for each frequency, must be employed. However, a single radio receiver which could receive more than one frequency would be more advantageous.